Rotary transfer mechanism for printing machines

ABSTRACT

THE GRIPPERS OF THE TRANSFER MECHANISM ARE ACTUATED BY A SWINGABLE AXLE CARRYING A CONTROL LEVER WITH A ROLLER TRAVELLING IN THE GROOVE OF A CAM. A GUIDE MEMBER IS SLIDABLY MOUNTED IN THE CAM AND IS OPERATED BY A BENT LEVER ACTUATED BY A CAM PLATE SO AS TO IMPART ROCKING MOVEMENT TO THE SWINGABLE AXIS. THE LATTER CARRIES SLEEVES WITH ABUTMENTS FOR GRIPPING THE PAPER SHEET AND WITH FINGERS, ADAPTED TO ENGAGE ABUTEMENT PINS COOPERATING WITH SET SCREWS TO CONTROL THE DEFLECTION OF THE GRIPPERS.

' J. JURNY 3,552,745

ROTARY TRANSFER MECHANISM FOR PRINTING MACHINES Jan.- 5, 1971 Filed Aug.20, 1968 705 6/ Turn);

7 INVENTOR. I

United States Patent O 3,552,745 ROTARY TRANSFER MECHANISM FOR PRINTINGMACHINES Josef Jurny, Sebranice u Kunstatu, Czechoslovakia, as-

signor to Adamovske strojirny, narodni podnik, Adamov, CzechoslovakiaFiled Aug. 20, 1968, Ser. No. 754,038 Claims priority, applicationCzechoslovakia, Aug. 28, 1967, 6,099/67 Int. Cl. B65h 29/06 US. Cl.271-82 3 Claims ABSTRACT OF THE DISCLOSURE BACKGROUND OF THE INVENTION(1) Field of the invention The present invention relates to a rotarytransfer mechanism constituting a device for the transfer of paper sheetinto the grippers of a printing roller in rotary sheet printingmachines.

(2) Description of the prior art One of the known devices comprises aswingable transfer mechanism with grippers which, having transferred thesheet to the printing roller, return to their original position along adifferent and slightly elevated path, in order to permit the returnmovement of the swingable grippers without interference with the passageof the preceding paper sheet over the feeder table. This operation isperformed by means of rotary excentric bushings, housing the main shaftof the swingable grippers. This coupled with an independent control ofthe transfer mechanism, renders the respective mechanism highlyintricate. Moreover, during each operative cycle of the transfermechanisms the latter have to be accelerated from their position of restwhen gripping the sheet, to the peripheral speed of the printing roller,then decelerated until they are completely stopped. Thereupon they mustbe again greatly accelerated during their return movement and againslowed down until they are completely stopped. The rate of accelerationis unfavourable particularly with an arrangement of the machine in whichthe angle of transfer from the feeder table exceeds 120, as for examplein five-roller systems as are used in two-colour printing machines.

For this reason it is necessary to use swingable transfer mechanismsplaced at a lower level and having a small angle of oscillation as wellas a further transfer drum.

These disadvantages are eliminated by the arrangement of rotary transfermechanisms, which after acceleration continue their rotary movementuntil they are stopped. The return movement necessary for gripping thesheet is negligible and connected with a minimum amount of acceleration.Consequently the respective mechanism as well as the proper transfermechanisms can be lighter in weight, so that at high speed they do notcause such a large impact as the previously mentioned heavy devices.Rotary transfer mechanisms can be employed advantageously also for largeangles of transfer, with the result that the further transfer drum maybe dispensed with. In connection with such known rotary transfermechanisms a tiltable "ice It is a disadvantage of this latter devicethat the entire conveying table, having a large mass, has to be movedwithin a relatively short time. This is the cause of considerable impactand harmful application of force on the machine.

SUMMARY OF THE INVENTION The present invention aims at removing theaforementioned disadvantages of the known rotary transfer mechanisms.The invention provides a swingable axle carrying, on the one handpivotally mounted sleeves to each of which is fixed a bar with anabutment plate and, on the other hand, fixed fingers adapted to bear onabutment pins fitted in the sleeves and bearing on set screws, which arearranged in holder secured to carrier discs supporting the axle. Fixedto the swingable axle is a control lever, provided with a roller adaptedto travel in the groove of a cam and along a track provided on a guidemember placed in a slot of said cam. The guide member is pivotallymounted on a pin fixed to one end of a bent lever. This bent lever,rotatably mounted on a pivot fixed in the sidewall of the machine, isprovided at one end with a control screw and with a groove for a safetyscrew, its other end carrying an eccentric pivot with a follower.

It is an advantage of the rotary transfer mechanisms according to theinvention that it is possible to execute the respective mechanisms aswell as their drive in a lighter Weight than before, so that impactsoccuring at higher revolutions of operation are minimized. The conveyingtable is stationary and the abutments are made tiltable in order toallow the passage of the grippers through the feeding plane. Thisarrangement is simple, light in weight and due to the fact that thecentre of rotation of the abutment bar is identical with the centre ofthe gripper mounting, it is sufliciently accurate. Moreover the gapbetween the abutments of the grippers of the rotary transfer mechanismsand the abutments of the printing roller can easily be adjusted inaccordance with the thickness of the sheet to be printed, with theresult that its accurate transfer is ensured.

BRIEF DESCRIPTION OF THE DRAWINGS The accompanying drawings show, by wayof example, one of the possible arrangements of the transfer mechanismaccording to the invention in a diagrammatic representation.

FIG. 1 is an elevation, partially in section, of the transfer mechanism,the grippers assuming a slightly deflected position,

FIG. 2 is a side view, partly in section taken along the line AA andshowing the parts in a position marked I in FIG. 5, and illustrates theposition at the moment when the sheet is picked up and the transfermovement begins,

FIG. 3 is a partial section along the line AA from FIG. 1 and representsthe position II of the parts, as shown in FIG. 5, and illustrates thetiltable grippers with the abutments prior to leaving the feed plane,

FIG. 4 is a partial section along the line AA from FIG. 1 at the momentwhen the grippers are opened, and

FIG. 5 shows the device in a section along the line BB from FIG. 1.

3 DESCRIPTION OF THE PREFERRED EMBODIMENT The rotary transfer mechanismaccording to the invention comprises a main shaft 1 journalled in thesidewalls 20 of a printing machine. Rigidly secured to the main shaft 1are spaced carrier discs 2, on which a swingable axle 3 is mounted forrotation. As seen in the figure, the axle 3 is parallel to but offsetfrom the axis of the shaft 1. Rockably fitted on the swingable axle 3are spaced sleeves supporting a bar 9 on which abutment plates 8 arelocated. Firmly secured to the swingable axle 3 are fingers 13 andholders 5, which are provided with screws 6, springs 7 and swingablymounted grippers 4. Fixed to one end of the swingable axle 3 is acontrol lever 21 carrying a roller 22 which is journalled on a pin 23and with a tensile spring 36, suspended on a stud 35 and on a suspensionpin 37, which is secured to the carrier disc 2. Each of the sleeves 10accommodate abutment pins 12, the outer sides of which are engaged byset screws housed in holders 14. Springs 11 are fitted in the sleeves 10resting against the main shaft 1.

The swingable axle 3 supports the control lever 21 with the roller 22,so that it travels in the groove of a cam 24. A guide member 27 extendsinto the cam 24 and is rockably mounted on a pin 28, secured in one armof a bent lever 25. The guide member 27 is further secured in positionby a safety screw 29, screwed in said arm of the bent lever 25 andpassing through a slot, provided in the guide member 27, so as to allowthe adjustment of its position by tilting the guide member 27 about thepin 28. The arm of the bent lever 25 houses further a control screw 30.The bent lever 25 is journalled on a pivot 26 rigidly secured in thesidewall of the printing machine. One end of the bent lever carries aneccentric pivot 32 on which a follower 31 is mounted for rotation, theroller being pressed by a spring 34 against a control cam plate 33. Thepaper sheets are supplied along a feed table 16 and are held in positionby pressure belts 18. Mounted opposite the discharge end of the feedtable 16 is a rockable front gauge 17.

The rotary transfer mechanism embodying the invention operates asfollows:

The paper sheets having been initially placed and adjusted in properposition, the bent lever 25 (FIG. 5) is shifted by means of the follower31 during rotation of the cam plate 33 from a position marked III to aposition I. Simultaneously the guide member 27 with the aid of theroller 22 and control lever 21 causes the swingable axis 3 to turn insuch a way, that the grippers 4, under the action of the pressure spring7, press the edge of the prepared sheet against the abutment plates 8.In this position a gap remains between the fingers 13 and the abutment12,. The gap secures the engagement of the abutment pin 12 with the setscrew 15 so as to ensure the basic position of the bar 9. After thesheet has been clamped, the front gauge 17 is deflected and the rotarytransfer mechanisms start an accelerating movement. The roller 22 passessmoothly from the operative surface of the guide member 27 in position Ito the groove, positioned in the cam 24 at the point where the curvatureof the groove forms a wave-line, causing the control lever 21 and thusthe swingable axle 3 to turn and open the grippers 4, when transferringthe sheet to the printing roller 19. The smooth blending of theoperative surface of the guide member 27, when in position 1, into thegroove of the cam 24 is adjusted by means of the eccentric pivot 32. Thespiral shape of the groove in the cam 24 causes during further movementof the control lever 21 another partial rotation of the swingable axle3, in such a way that the grippers 4 are reclosed. The continuingrotation of the swingable axis 3 causes the finger 13 to abut againstthe abutting pins 12.

In this way the springs 11 are depressed and the sleeves 10, togetherwith the bar 9 and abutment plates 8, begin to effect a tilting motionso that at the moment when the grippers 4 are in a position above thefront gauge 17, they are tilted to a position II (see FIG. 3), to enablethe passage of the remaining part of the Withdrawn sheet, while thefollowing sheet is already prepared and properly positioned on thetiltable front gauge 17. The roller 22 of the control lever 21 travelsin this position along the operative surface of the guide member 27 inthe position II, which joins the groove provided in the cam 24; thesmooth blending can be adjusted by means of the set screw 30.

At the moment when the end of the preceding paper sheet has left thefeed plane, the rotary transfer mechanisms are already at rest and it isonly the bent lever 25 which is in motion by the action of the controlcam plate 33 and follower 31 in such a way that the operative surface ofthe guide member 27 drops from position II into position III. By theaction of the roller 22 and control lever 21 the swingable axis 3, aswell as the fingers 13, are slightly rotated. This movement causes theabutment pins 12 to engage the set screws 15, with the result that themovement of the sleeve 10, bar 9 and abutment plates 8 is stopped. As,however, the rotary movement of the swingable axis 3 and of the holders5 continues, the grippers 4 are opened (FIGS. 4 and 5) and after therotary transfer mechanisms have been turned back and the grippers closedin the manner described above, the whole cycle of operation is repeated.

The drive of the main shaft 1 and consequently also of the transfermechanisms is derived from a not-illustrated mechanism consisting of camdiscs, rollers and toothed segments, which transmit the movement fromthe printing roller. In order to eliminate any inaccuracy in thetransfer which may be caused by the undulation of a thin paper sheet,the gap between the abutment plates 8 may be adjusted by means of theset screws 15 provided with a scale, so as to alter the distance of theabutment plates 8 from the axis of the main shaft 1.

I claim:

1. In a device for the transfer of pre-positioned paper sheets into thegrippers of a printing roller in rotary sheet printing machines, arotary transfer mechanism, comprising a machine frame, a main shaftmounted for rotation in said machine frame, means for imparting rotarymovement to the main shaft, spaced carrier discs firmly secured to themain shaft, a swingable axle parallel to said shaft and mounted forrotary movement in said carrier discs, means for imparting partialrotary movement to the swingable axle in relation to the carrier discs,spaced sleeves mounted for rocking movement on the swingable axle, asupporting bar having an abutment plate fixed to each of said sleevesfor rocking movement therewith, an abutment pin fixedly mounted in eachof said sleeve, a pair of spaced fingers rigidly fixed to the swingableaxle and adapted to engage each of the abutment pins respectively, screwmeans carried by said carrier discs and adapted to engage each of saidabutment pins respectively.

2. In a device for the transfer of pre-positioned paper sheets into thegrippers of a printing roller in rotary sheet printing machines, arotary transfer mechanism, comprising a machine frame, a main shaftmounted for rotation in said machine frame, means for imparting rotarymovement to the main shaft, spaced carrier discs firmly secured to themain shaft, a swingable axle parallel to said shaft and mounted forrotary movement in said carrier discs, means for imparting partialrotary movement to the swingable axle in relation to the carrier discs,spaced sleeves mounted for rocking movement on the swingable axle, asupporting bar having an abutment plate fixed to each of said sleevesfor rocking movement therewith, an abutment pin fixedly mounted in eachof said sleeve, a pair of spaced fingers rigidly fixed to the swingableaxle and adapted to engage each of the abutment pins respectively, screwmeans carried by said carrier discs and adapted to engage each of saidabutment pins respectively, a control lever is fixed to the swingableaxle carrying a roller and includes a grooved cam and a guide memberlocated in a slot formed in said cam, said roller adapted to travel, onthe one hand, in the groove provided in a cam and, on the other hand,along the operative surface of a guide member, the guide member beingfurther mounted for adjustment on one arm of a bent lever, controlled bya control cam plate.

3. A rotary transfer mechanism as in claim 2, wherein the bent lever isjournalled on a pin fixed in the frame of the machine, and is providedat one end with a control screw and With a groove for a safety screw,its other end being provided with an eccentric pivot carrying afollower, cooperating with said control cam plate.

References Cited FOREIGN PATENTS 602,045 5/1948 Great Britain 27l82 0RICHARD AEGERTER, Primary Examiner

